/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina.ha.session;

import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.Serializable;
import java.security.Principal;
import java.util.Arrays;
import java.util.List;

import org.apache.catalina.Realm;
import org.apache.catalina.realm.GenericPrincipal;
import org.apache.catalina.util.StringManager;

/**
 * Generic implementation of <strong>java.security.Principal</strong> that is
 * available for use by <code>Realm</code> implementations. The
 * GenericPrincipal does NOT implement serializable and I didn't want to change
 * that implementation hence I implemented this one instead.
 * 
 * @author Filip Hanik
 * @version $Revision: 610930 $ $Date: 2008-01-11 05:09:27 +0800 (星期五, 11 一月
 *          2008) $
 */
public class SerializablePrincipal implements java.io.Serializable {

	protected static org.apache.juli.logging.Log log = org.apache.juli.logging.LogFactory
			.getLog(SerializablePrincipal.class);

	/**
	 * The string manager for this package.
	 */
	protected static StringManager sm = StringManager
			.getManager(Constants.Package);

	// ----------------------------------------------------------- Constructors

	public SerializablePrincipal() {
		super();
	}

	/**
	 * Construct a new Principal, associated with the specified Realm, for the
	 * specified username and password.
	 * 
	 * @param realm
	 *            The Realm that owns this Principal
	 * @param name
	 *            The username of the user represented by this Principal
	 * @param password
	 *            Credentials used to authenticate this user
	 */
	public SerializablePrincipal(Realm realm, String name, String password) {

		this(realm, name, password, null);

	}

	/**
	 * Construct a new Principal, associated with the specified Realm, for the
	 * specified username and password, with the specified role names (as
	 * Strings).
	 * 
	 * @param realm
	 *            The Realm that owns this principal
	 * @param name
	 *            The username of the user represented by this Principal
	 * @param password
	 *            Credentials used to authenticate this user
	 * @param roles
	 *            List of roles (must be Strings) possessed by this user
	 */
	public SerializablePrincipal(Realm realm, String name, String password,
			List<String> roles) {
		this(realm, name, password, roles, null);
	}

	/**
	 * Construct a new Principal, associated with the specified Realm, for the
	 * specified username and password, with the specified role names (as
	 * Strings).
	 * 
	 * @param realm
	 *            The Realm that owns this principal
	 * @param name
	 *            The username of the user represented by this Principal
	 * @param password
	 *            Credentials used to authenticate this user
	 * @param roles
	 *            List of roles (must be Strings) possessed by this user
	 * @param userPrincipal
	 *            The user principal to be exposed to applications
	 */
	public SerializablePrincipal(Realm realm, String name, String password,
			List<String> roles, Principal userPrincipal) {

		super();
		this.realm = realm;
		this.name = name;
		this.password = password;
		if (roles != null) {
			this.roles = new String[roles.size()];
			this.roles = roles.toArray(this.roles);
			if (this.roles.length > 0)
				Arrays.sort(this.roles);
		}
		if (userPrincipal instanceof Serializable) {
			this.userPrincipal = userPrincipal;
		}
	}

	// ------------------------------------------------------------- Properties

	/**
	 * The username of the user represented by this Principal.
	 */
	protected String name = null;

	public String getName() {
		return (this.name);
	}

	/**
	 * The authentication credentials for the user represented by this
	 * Principal.
	 */
	protected String password = null;

	public String getPassword() {
		return (this.password);
	}

	/**
	 * The Realm with which this Principal is associated.
	 */
	protected transient Realm realm = null;

	public Realm getRealm() {
		return (this.realm);
	}

	public void setRealm(Realm realm) {
		this.realm = realm;
	}

	/**
	 * The set of roles associated with this user.
	 */
	protected String roles[] = new String[0];

	public String[] getRoles() {
		return (this.roles);
	}

	/**
	 * The user principal, if present.
	 */
	protected Principal userPrincipal = null;

	// --------------------------------------------------------- Public Methods

	/**
	 * Return a String representation of this object, which exposes only
	 * information that should be public.
	 */
	public String toString() {

		StringBuffer sb = new StringBuffer("SerializablePrincipal[");
		sb.append(this.name);
		sb.append("]");
		return (sb.toString());

	}

	public static SerializablePrincipal createPrincipal(
			GenericPrincipal principal) {
		if (principal == null)
			return null;
		return new SerializablePrincipal(principal.getRealm(), principal
				.getName(), principal.getPassword(),
				principal.getRoles() != null ? Arrays.asList(principal
						.getRoles()) : null,
				principal.getUserPrincipal() != principal ? principal
						.getUserPrincipal() : null);
	}

	public GenericPrincipal getPrincipal(Realm realm) {
		return new GenericPrincipal(realm, name, password,
				getRoles() != null ? Arrays.asList(getRoles()) : null,
				userPrincipal);
	}

	public static GenericPrincipal readPrincipal(ObjectInput in, Realm realm)
			throws IOException, ClassNotFoundException {
		String name = in.readUTF();
		boolean hasPwd = in.readBoolean();
		String pwd = null;
		if (hasPwd)
			pwd = in.readUTF();
		int size = in.readInt();
		String[] roles = new String[size];
		for (int i = 0; i < size; i++)
			roles[i] = in.readUTF();
		Principal userPrincipal = null;
		boolean hasUserPrincipal = in.readBoolean();
		if (hasUserPrincipal) {
			try {
				userPrincipal = (Principal) in.readObject();
			} catch (ClassNotFoundException e) {
				log.error(sm
						.getString("serializablePrincipal.readPrincipal.cnfe"),
						e);
				throw e;
			}
		}
		return new GenericPrincipal(realm, name, pwd, Arrays.asList(roles),
				userPrincipal);
	}

	public static void writePrincipal(GenericPrincipal p, ObjectOutput out)
			throws IOException {
		out.writeUTF(p.getName());
		out.writeBoolean(p.getPassword() != null);
		if (p.getPassword() != null)
			out.writeUTF(p.getPassword());
		String[] roles = p.getRoles();
		if (roles == null)
			roles = new String[0];
		out.writeInt(roles.length);
		for (int i = 0; i < roles.length; i++)
			out.writeUTF(roles[i]);
		boolean hasUserPrincipal = (p != p.getUserPrincipal() && p
				.getUserPrincipal() instanceof Serializable);
		out.writeBoolean(hasUserPrincipal);
		if (hasUserPrincipal)
			out.writeObject(p.getUserPrincipal());
	}

}
